Evolution of material properties with respect to the global coordinates

30 November 2013

by P. Sémété, EDF R&D / MMC et J. Delmas, EDF R&D / AMA

Until recently, in order to assign material properties to an heterogeneous structure, one needed to prepare the required groups at the very beginning in the mesh (with one group of elements for each different value of the property). Besides, this process was to be repeated for each different configuration of the material zoning.

From now on, there exists a simple and direct way to define the evolution of a material property with respect to the global coordinates (X, Y, Z) by chaining the operators FORMULE, DEFI_MATERIAU and AFFE_MATERIAU.

The example below illustrates how multiple zoning configurations of material properties were represented on a unique mesh. In this study, one wishes to simulate the mechanical behavior of a structure whose material has deteriorated. This is done with a Young modulus which changes to account for sound and damaged zones.

Figure 1 : Structure with a damaged material on one third of its thickness

Figure 2 : Structure with a damaged material on one half of its thickness

Three different configurations for the Young modulus field were analyzed in this study :

structure with an abruptly damaged material on one third of its thickness over the outer border (figure 1),

structure with an abruptly damaged material on one half of its thickness over the outer border (figure 2),

structure with a progressively damaged material on the wall only (figure 3).

Figure 3 : Structure with a transition zone between sound and damaged material

Only a few lines in the command file and one mesh were required to represent such different cases.

Every material properties which can be defined as functions may benefit from this new feature.